Re: [Haskell-cafe] Docs on the current and future constraint solver?

On Thu, Jul 15, 2010 at 12:57 AM, Simon Peyton-Jones wrote:

Corey

| On 14 July 2010 18:39, Corey O'Connor wrote: | > I believe I have run headlong into issue #3064 in ghc | > (http://hackage.haskell.org/trac/ghc/ticket/3064). All I think I know | > is this: | > * this is a performance issue with the system used to solve type | constraints. | > * the solver is undergoing an overhaul to resolve performance issues | > in addition to other issues. | > * An efficient constraint solver is difficult. NP-Complete in the general | case?

It would be very helpful to have your code as a test case. Can you boil out a concrete program that demonstrates very poor performance of the type checker, and submit a Trac report?  That way we'll test the new type inference engine against it.  Lacking the example, we won't.

Which is isn't a promise that we'll solve your problem -- but it's much easier to solve if we have a concrete example.  Many thanks!

Understood. I'll work on getting a nice, self-contained example. Cheers, Corey O'Connor